Chickens should eat balanced diet that consists primarily of high quality poultry pellets and grains, such as corn and wheat, according to RSPCA.org. Fresh raw vegetables and fruits, such as spinach, chickweed, endive, bananas, silverbeat, cabbage and bok choy, should also be part of a chicken's daily diet.
Other foods, such as rolled oats, bread, legumes, beans and cooked pasta, can supplement a chicken's diet. Chickens that lay eggs require a sufficient amount of calcium, which can be obtained by grinding egg shells that are high in calcium into a powder and then mixing it with their normal feed. Finally, any food scraps fed to chickens should not be spoiled and should not contain high amounts of salt or fat.